I suggest being reassured by the results of your 24 hour test and trying to relax and forget about your bp for the time being. I daresay it goes up from time to time due to your understandable anxiety, but clearly the picture overall is good. GPs do worry about bp, so if your GP says yours is fine, I would accept that. You have enough to focus on in, as you say, learning about blood glucose and low carb, and in doing that you can make a real difference to your health and future. A low carb diet often brings bp down. In my case, I have always had rather low bp. After lowering my carbs a lot, I was worried about my much increased salt intake. I thought it might have raised my bp, but no such thing. My bp is if anything lower than before.
Please don't feel ashamed that you ate high carb for many years. So did I and many other people. We were advised to do so, and we were certainly not advised to eat low carb high fat! It's great that you are enjoying learning about all this, and that you are making such an effort. Good luck!